On such occasions Father Absinthe planted his cane in the earth, near the last footprint that had been discovered, and Lecoq and himself hunted all over the ground around this point, much after the fashion of a couple of bloodhounds thrown off the scent.  Then it was that the lantern moved about so strangely.  More than a dozen times, in spite of all their efforts, they would have lost the clue entirely had it not been for the elegant shoes worn by the lady with the little feet.  These had such small and extremely high heels that the impression they left could not be mistaken.  They sank down three or four inches in the snow, or the mud, and their tell-tale impress remained as clear and distinct as that of a seal.

Thanks to these heels, the pursuers were able to discover that the two fugitives had not gone up the Rue de Patay, as might have been supposed.  Probably they had considered this street too frequented, and too well lighted.  They had only crossed it, just below the Rue de la Croix-Rouge, and had profited by an empty space between two houses to regain the open ground.

“Certainly these women were well acquainted with the locality,” murmured Lecoq.

Indeed, the topography of the district evidently had no secrets for them, for, on quitting the Rue de Patay, they had immediately turned to the right, so as to avoid several large excavations, from which a quantity of brick clay had been dug.

But at last the trail was recovered, and the detectives followed it as far as the Rue du Chevaleret.  Here the footprints abruptly ceased.  Lecoq discovered eight or ten footmarks left by the woman who wore the broad shoes, but that was all.  Hereabout, moreover, the condition of the ground was not calculated to facilitate an exploration of this nature.  There had been a great deal of passing to and fro in the Rue du Chevaleret, and not merely was there scarcely any snow left on the footpaths, but the middle of the street was transformed into a river of slush.

“Did these people recollect at last that the snow might betray them?  Did they take the middle of the road?” grumbled the young police agent.

Certainly they could not have crossed to a vacant space as they had done just before, for on the other side of the street extended a long factory wall.

“Ah!” sighed Father Absinthe, “we have our labor for our pains.”

But Lecoq possessed a temperament that refused to acknowledge defeat.  Animated by the cold anger of a man who sees the object which he was about to seize disappear from before his eyes, he recommenced his search, and was well repaid for his efforts.

“I understand!” he cried suddenly, “I comprehend—­I see!”

Father Absinthe drew near.  He did not see nor divine anything! but he no longer doubted his companion’s powers.

“Look there,” said Lecoq; “what are those marks?”

“Marks left by the wheels of some carriage that plainly turned here.”